feat(mesh): rnode-config RPCs + honest reboot feedback with reply channels

- mesh.rnode-config: persisted RF settings + best-effort live radio
  state (radio-confirmed r_* values) for the LoRa panel.
- mesh.rnode-config-apply: validate → persist → restart the radio
  daemon → poll the read-back until the radio reports online, returning
  {applied, confirmed, live, message}. Failure modes report what
  actually happened instead of pretending success.
- RebootRadio carries a reply channel: Meshtastic reboots firmware,
  Reticulum restarts the sidecar (re-detect + reapply RF config),
  MeshCore honestly reports it has no remote reboot — previously the
  Reticulum/MeshCore arms returned Ok(()) doing NOTHING: the operator's
  "button gives no feedback" bug.
- MeshCommand::QueryRadioState plumbs the sidecar's radio_state to the
  service layer with a timeout instead of fire-and-forget.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

core/archipelago/src/api/rpc/dispatcher.rs

@@ -405,6 +405,8 @@ impl RpcHandler {
             "mesh.send-channel" => self.handle_mesh_send_channel(params).await,
             "mesh.broadcast" => self.handle_mesh_broadcast().await,
             "mesh.reboot-radio" => self.handle_mesh_reboot_radio(params).await,
+            "mesh.rnode-config" => self.handle_mesh_rnode_config().await,
+            "mesh.rnode-config-apply" => self.handle_mesh_rnode_config_apply(params).await,
             "mesh.configure" => self.handle_mesh_configure(params).await,
             "mesh.send-invoice" => self.handle_mesh_send_invoice(params).await,
             "mesh.send-coordinate" => self.handle_mesh_send_coordinate(params).await,